Known ferroelectric readback methods are either excessively complex and costly or inherently erase data that is being read. In ferroelectric storage devices, information is stored in ferroelectric domains. For writing data into the ferroelectric material, small ferroelectric domains are formed by locally applying an electrical field with a very small tip. For reading the data back, various methods are available, including piezo-force-microscopy (PFM), scanning-nonlinear-dielectric-microscopy (SNDM), and erase read-back (ERB). All three methods have certain disadvantages for the electrode storage application. PFM and SNDM both require complicated measurement instruments. PFM requires an atomic force microscopy (AFM) like setup to measure the very small height change, whereas SNDM requires a microwave resonator, an oscillator and a FM demodulator to measure the local dielectric response. ERB senses the polarization currents by switching all domains into one polarization state, which erases the stored information. Therefore after reading the data, the data must be rewritten.
A method and apparatus are needed for reading data from ferroelectric storage media without erasing the data and without complex, expensive, high power readback mechanisms. Aspects of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.